Synthetic resin bottle

ABSTRACT

There is provided a synthetic resin bottle that can be fully flattened and easily restored to its original shape. The bottle has the following configuration: At least a line of turn is formed on the shoulder, the body, and the bottom along the entire vertical circumference. Among the sections divided by this line of turn, at least a section is used as a shell section in which at least a nearly entire body portion of this section has relatively high rigidity. The other section is a reversible section in which at least a nearly entire body portion has relatively low rigidity and is capable of being deformed by resilient reversion. The neck is disposed on the shoulder, and the reversible section can be deformed and easily concaved into the shell section for volume reduction and then can be restored to the original shape.

TECHNICAL FIELD

This invention relates to a synthetic resin bottle of a configurationthat the bottle can be deformed to reduce its volume easily and then isrestored to its original shape for use as a bottle.

BACKGROUND OF THE INVENTION

Synthetic resin bottles are in wide use as the containers for variousliquid contents. These bottles are molded by using blow molding orbiaxial-drawing, blow-molding means.

This synthetic resin bottle has an advantage of lightweight. On theother hand, because of bulkiness and large space of occupancy, a problemof high storage and transportation costs are caused during the processin which bottles are molded by the bottle manufacturers, delivered toproduct manufacturers, and filled with liquids. Handling of bulkybottles is also troublesome.

After use, the used bottles are usually flattened with hands or feet toreduce the volume of the bottle and to facilitate waste disposal. Thebottles had a problem in that everyone cannot always flatten bottleseasily and steadily.

Utility model laid open No. 1985-75212 describes a technique aimed ateasily flattening bottles at the time of waste disposal.

The synthetic resin bottle described in this utility model is providedwith a pair of ribs at the axisymmetric positions on the body. Inaddition to these ribs, arc ribs are also provided on the shoulder andat the lower end of the body. When the bottle is put to waste disposal,the portion surrounded by the ribs is pressed to let the body cave inand deform so that volume reduction can be achieved.

However, in this conventional art, the concaved portion ranges from theshoulder to the lower end of the body, with neck and bottom retainingthe original shapes. Because of this limitation, the bottle had troublein that the entire bottle cannot be pressed flat and deformed. Sincethese ribs are aimed at flattening the bottle at the time of wastedisposal, it was almost impossible to restore the original shape of thebottle once the bottle has been forced to cave in.

This invention has thus been made to solve the problems of theabove-described conventional art. The technical problem of thisinvention is to deform the bottle easily in a volume-reducing manneruntil the bottle is fully flat and then to be able to restore theoriginal shape as a bottle from the flat or concaved state. Thus, anobject of this invention is to make bottle handling easy and efficientduring the process from molding to the filling of bottles with contentsand at the time of bottle disposal as waste,and the reduction of thecost.

DISCLOSURE OF THE INVENTION

The means of carrying out the invention of claim 1 to solve theabove-described technical problems exists in the configurationcomprising:

-   -   that at least a line of turn is formed on the shoulder, the        body, and the bottom along the entire vertical circumference;    -   that among the sections divided by this line of turn, at least a        section is used as a shell section in which at least a nearly        entire body portion of this section has relatively high        rigidity;    -   that the other section is a reversible section in which at least        a nearly entire body portion of this section has relatively low        rigidity and is capable of being deformed by resilient        reversion;    -   that the neck is disposed on the shoulder; and    -   that the reversible section can be deformed and easily concaved        into the shell section and then can be restored to the original        shape.

Owing to the above configuration of claim 1, the bottle molded by thebottle manufacturer is reversed from the line of turn by pressing theless rigid reversible section inward and concaving this section towardthe inside of the shell section to reduce the volume of the bottle.

Commercial product manufacturers should be able to reverse the concavedreversible section again outward, by using air pressure and the like, torestore the original shape. The restored bottle can then be filled witha liquid content to complete a commercial product. Or the manufacturerscan fill the concaved bottle directly with a liquid content. In thatcase, the liquid filling force acts on the concaved reversible sectionto turn the section outward. The liquid filling operation is continueduntil the bottle is full and ready for merchandising.

When the bottle is used and discarded as waste, the reversible sectionis again concaved to reduce the volume, and the flattened bottle isdisposed of as waste.

The means of carrying out the invention of claim 2 exists in theconfiguration that in the invention of claim 1, a line of turn is formedat the position dividing the plan-view shapes of the shoulder, the body,and the bottom into two equal, right and left, parts; that the shellsection comprises a major-diameter portion, which is a half on one sideof this line of turn, where the plan view of the body roughly forms anarc-like convex surface having a larger diameter; and that thereversible section comprises a minor-diameter portion, which is theremaining half on the other side of this line of turn, where the planview of the body roughly forms an arc-like convex surface having asmaller diameter.

Because of the above configuration according to claim 2, the reversiblesection protruding in an arc-like convex surface can be deformed inwardand concaved into the inside of the shell section protruding likewise inan arc-like convex surface but having a larger diameter than thereversible section. Thus, it is possible to flatten the bottle in acertain shape. Since the flat bottles can be easily piled up, thebottles before use can be stored and transported, or the bottles afteruse can be handled for waste disposal, more efficiently and at a lowercost than the bottles retaining the original shape.

The means of carrying out the invention of claim 3 exists in theconfiguration that in the invention of claim 2, the neck is disposed soas to stand on the shoulder at the upper end of the shell section.

Because, in the above configuration according to claim 3, the neck isdisposed on the shell section side, the entire bottle can be flattenedwithout crushing the neck. Therefore, it is possible to concave anddeform easily the halves of the shoulder, the body, and the bottom, oralmost a half of the bottle.

The means of carrying out the invention of claim 4 exists in theconfiguration that, in the invention of claim 2, the neck is disposed tostand in the center of the shoulder and that a line of turn is formed atthe position dividing the plan-view shapes of the shoulder, the body,and the bottom axisymmetrically into two equal, right and left, parts.

Because, in the above configuration according to claim 4, a shellsection and a reversible section are formed also at the neck, the entirebottle can be fully flattened to reduce the volume, over all the heightfrom neck to bottom.

The means of carrying out the invention of claim 5 exists in theconfiguration that, in the invention of claim 1, a pair of lines of turnis formed at roughly symmetrical positions in the plan view of theshoulder, the body, and the bottom; that among the sections divided bythese two lines of turn, the shell section is the central portion whereside walls of the body face each other; and that the reversible sectionsare the two portions disposed on both sides of the shell section, witheach reversible section having an arc-like convex surface protrudingoutward in the plan view of the body.

In the configuration according to claim 5, the bottle can be deformedand concaved into the inside of the shell section located in the center,by pressing both reversible sections inward to reverse these sectionresiliently. As a result, both reversible sections are concaved andaccommodated inside the shell section, where the plan-view shape of theentire body including the bottom roughly forms a rectangle. Thus, itbecomes possible to flatten the bottle to an extent enough to reduce itsvolume.

The bottle according to claim 5 excels at bottle handling because thebottle stands fully on its own due to the shell section in the center.

The means of carrying out the invention of claim 6 exists in theconfiguration that, in the invention of claim 1, 2, 3, 4, or 5, thebottle is molded from a relatively soft synthetic resin so as to have athin wall and that on at least either one of the inner surface or theouter surface of the shell section, the most part of at least the bodysurface is laminated with another layer.

In the above configuration according to claim 6, the laminated bottlewall is given higher rigidity than the non-laminated wall portion, wherethe bottle is molded to have a thin wall. Since there is no need tochange the wall thickness of the bottle itself, the bottles can beeasily manufactured by means of an ordinary blow molding method, whilesecuring high productivity.

The means of carrying out the invention of claim 7 exists in theconfiguration that, in the invention according to claim 6, a relativelythick, hard label is laminated over the outer surface of the body.

In the above configuration according to claim 7, a label is laminatedover the entire outer surface of at least the body portion in onesection of the bottle divided by the line of turn. This label enablesthe shell section to be formed easily at a low cost. High decorativeeffect and high display effect can be obtained since it is possible forthe label to have a wide display area.

In addition, the rigidity of the shell section is fully enhanced, andthe bottle shows high shape-holding power. Because of these features,the bottle shape becomes stabilized and constant when the bottle isdeformed for volume reduction and when it is restored to the originalshape. The bottle can be allowed to have thin walls with no difficulty,by making the label serve as a structural material.

The means of carrying out the invention of claim 8 exists in theconfiguration that, in the invention of claim 1, 2, 3, 4, or 5, theshell section of the bottle is molded so as to have an ordinary thickwall, with the reversible section being molded so as to have arelatively thin wall.

In the above configuration according to claim 8, the shell section andthe reversible section can be formed simultaneously with the molding ofthe bottle. Depending on the parts of the bottle, the wall thicknessratio of the shell section to the reversible section is changed so thatthe rigidity of both sections may be adjusted finely and precisely.Thus, it becomes quite easy to reverse the reversible section of theentire bottle toward the shell section and in turn to restore theoriginal bottle shape.

The means of carrying out the invention of claim 9 exists in theconfiguration that, in the invention of claim 1, 2, 3, 4, 5, 6, 7, or 8,the line of turn comprises a sloped step.

In the above configuration according to claim 9, the line of turn has asloped step structure, which makes it easy to reverse and deform thereversible section and makes it much easier for the reversible sectionto be concaved and then restored to its original shape. Since thereversible section is deformed and reversed without causing permanentdeformation, no outer appearance is damaged by reversible deformation.

The means of carrying out the invention of claim 10 exists in theconfiguration that, in the invention of claim 1, 2, 3, 4, 5, 6, 7, or 8,the line of turn comprises a shallow V-shape groove.

In the above configuration according to claim 10, the reversible sectioncan be reversed quite easily and precisely.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partly cross-sectional side view showing the firstembodiment of this invention.

FIG. 2 is a partly cross-sectional plan view of the embodiment shown inFIG. 1.

FIG. 3 is a side view showing the second embodiment of this invention.

FIG. 4 is a front elevational view of the embodiment shown in FIG. 3.

FIG. 5 is a partly cross-sectional plan view of the embodiment shown inFIG. 3.

FIG. 6 is a partly cross-sectional side view showing the thirdembodiment of this invention.

FIG. 7 is a partly cross-sectional plan view of the embodiment shown inFIG. 6.

FIG. 8 is a partly broken, plan view showing the fourth embodiment ofthis invention.

FIG. 9 is a partly cross-sectional side view showing the fifthembodiment of this invention.

FIG. 10 is a partly cross-sectional plan view of the embodiment shown inFIG. 9.

FIG. 11 is a partly broken, front elevational view showing the sixthembodiment of this invention.

FIG. 12 is a partly broken plan view of the embodiment shown in FIG. 11.

FIG. 13 is a side view of the embodiment shown in FIG. 11.

PREFERRED EMBODIMENTS OF THE INVENTION

This invention is further described as to its preferred embodiments, nowreferring to the drawings.

FIGS. 1 and 2 show a synthetic resin bottle in the 1st embodiment ofthis invention. The bottle 1 is formed by blow molding a suitablesynthetic resin material so that the plan view of the bottle 1 has aroughly elliptic shape. A cylindrical neck 11 is disposed to stand onthe shoulder 2 on one side of the long axis of the ellipse.

A line of turn 5 in the shape of a sloped step is disposed at thepositions on the long axis, i.e., at the axisymmetrical positions of thebottle 1, around the entire circumference in the vertical direction ofthe bottle 1, including the shoulder 2, the body 3, and the bottom 4.

A major-diameter portion 6 occupies a half of the bottle 1 as divided bythis line of turn 5 (the left side in FIG. 1). This portion is molded tohave an ordinary thick wall and is used as the shell section 8, whichhas relatively high rigidity and is easy to grab.

The minor-diameter portion 9 occupies the other half of the bottle 1 asdivided by the line of turn 5 (the right side in FIG. 1). This portion 9has a somewhat smaller diameter and a thinner wall thickness than themajor-diameter portion 6 and is used as the reversible section 10, whichcan be deformed in a resiliently reversible manner.

Therefore, this reversible section 10 is resiliently reversed simply bypressing it inward, with the line of turn 5 serving as the fulcrum. Thereversible section 10 is entirely concaved into the inside of the shellsection 8, as shown by a chain double-dashed line in FIGS. 1 and 2, andcan be easily restored to its original shape by applying a force in theopposite direction and reversing this section outward.

Because of relatively high rigidity, the shell section 8 has also a goodbuckling strength and the hardness enough to be able to grab the bottle.Therefore, the bottle can be held and handled in the same way asordinary bottles. The bottle of this invention has no disadvantage ofconventional volume-reducing bottles, which are too soft to hold thebottle firmly with a hand.

It is preferred that the reversible section 10 has a wall thickness ⅔ orless of the shell section 8.

FIGS. 3-5 show a synthetic resin bottle in the 2nd embodiment of thisinvention. The overall shape of the bottle 1, the shape and position ofthe line of turn 5, and the like, are similar to those of the bottle inthe 1st embodiment. FIGS. 3-5 show a cap 12 that has been fitteddetachably around neck 11.

The bottle 1 is molded by blow molding a suitable, relatively softsynthetic resin to give a thin wall thickness on the whole and to have aroughly elliptic shape in its entire plan view.

A hard, relatively thick label 7 a of a paper material is attached tonearly all the outer surface of the body 3 in the major-diameter portion6 by means of insert molding or lamination. This major-diameter portion6 is used as the shell section 8 having relatively high rigidity; thethin minor-diameter portion 9 is used as the reversible section 10.

This reversible section 10 is resiliently reversed simply by pressing itinward, with the line of turn 5 serving as the fulcrum. The reversiblesection 10 is entirely concaved into the inside of the shell section 8,as shown by a chain double-dashed line in FIGS. 3 and 5, and can beeasily restored to its original shape by applying a force in theopposite direction and reversing this section outward.

Because of relatively high rigidity, the shell section 8 has also a goodbuckling strength and the hardness enough to be able to grab the bottle.Therefore, the bottle can be held and handled in the same way asordinary bottles. The bottle of this invention has no disadvantage ofconventional volume-reducing bottles, which are too soft to hold thebottle firmly with a hand.

If a thick, hard paper material is used as the label 7 a, the bottle 1is able to maintain its own shape stably, and further thin wall can bepromoted for the bottle 1. Depending on how much wall thickness can bereduced, easy bottle handling can be achieved for waste disposal.

FIGS. 6 and 7 show a synthetic resin bottle in the 3rd embodiment ofthis invention. The overall shape of the bottle 1, the shape andposition of the line of turn 5, and the like, are similar to those ofthe bottle in the 1st or 2nd embodiment. The bottle 1 is molded by blowmolding a relatively soft synthetic resin, such as low-densitypolyethylene, to have a thin wall thickness and to give the bottle 1 aroughly elliptic shape in its plan view.

Furthermore, the entire outer surface of the major-diameter portion 6 islaminated with an outer layer 7 b by means of insert molding orco-extrusion. This outer layer 7 b is made of a relatively hardsynthetic resin material, such as high-density polyethylene, so that themajor-diameter portion 6 can be sufficiently used as the shell section 8having high rigidity.

Like the 1st and 2nd embodiments, the reversible section 10 in the 3rdembodiment is resiliently reversed simply by pressing it inward, and isentirely concaved into the inside of the shell section 8, as shown by achain double-dashed line in FIGS. 6 and 7. The reversible section 10 canthen be easily restored to its original shape by applying a force in theopposite direction and reversing this section outward.

Because of the lamination with a relatively hard synthetic resinmaterial, such as high-density polyethylene, the shell section 8 hashigh rigidity and also a good buckling strength and the hardness enoughto be able to grab the bottle. Therefore, the bottle can be held andhandled in the same way as ordinary bottles. The bottle of thisinvention has no disadvantage of conventional volume-reducing bottles,which are too soft to hold the bottle firmly with a hand, and shows astable “seating” function due to its high rigidity. If necessary, legsmay be disposed under the bottom.

FIG. 8 shows a synthetic resin bottle in the 4th embodiment of thisinvention. Unlike the 3rd embodiment, in which the outer layer 7 b islaminated to form the shell section 8, the 4th embodiment employs ameans of co-extrusion, etc., to laminate an inner layer 7 c over theentire inner surface of the major-diameter portion 6. This inner layer 7c is made of a relatively hard synthetic resin material, such ashigh-density polyethylene, and thus, the inner layer 7 c turns themajor-diameter portion 6 into the shell section 8 having high rigidity.

FIGS. 9 and 10 show a synthetic resin bottle in the 5th embodiment ofthis invention. In the 1st embodiment, the cylindrical neck 11 isdisposed to stand on the shoulder 2 on the side of the shell section 8of the bottle 1. In contrast, the neck 11 in the 5th embodiment isdisposed at the center of the shoulder 2. The bottle 1 is formed by blowmolding a relatively soft synthetic resin material, such as apolyethylene resin, so that the bottle 1 in its plan view has a shapeobtained by abutting and connecting to each other the roughly semi-archalves of the bottle 1 including the neck 11, with the halves havingsomewhat different diameters.

As in the 1st embodiment, the major-diameter portion 6 of the bottle 1in the 5th embodiment comprises a half section on one side of the lineof turn 5 (the left side in FIG. 9) and has an ordinary thick wall. Thisportion 6 is thus used as the shell section 8, which has relatively highrigidity and is easy to grab with a hand. The minor-diameter portion 9on the other side of the line of turn 5 (the right side in FIG. 9) has asomewhat smaller diameter than the major-diameter portion 6. Thisportion 9 has a thin wall and is used as the reversible section 10,which can be resiliently reversed toward the shell section 8 or outwardin the opposite direction.

The bottle 1 is formed so that the plan view shows a roughly ellipticshape. The line of turn 5 is a sloped step built on the neck 11, theshoulder 2, the body 3, and the bottom 4, extending along the entirevertical circumference at the axisymmetrical positions on the long axisof a hypothetical plane, i.e., at the positions where two roughly arcsections with different diameters are abutted to each other.

Therefore, the reversible section 10 is resiliently reversed by pressingit inward, and is concaved into the inside of the shell section 8 (Seethe chain two-dash line in FIGS. 9 and 10). In this state the bottle 1is transported, handled, or disposed of as waste. When an outward forceis applied to the reversible section 10 to reverse it again in theopposite direction, the bottle easily restores its original shape andcan be used as a container.

Once the bottle in this embodiment has been filled with a certain amountof liquid content, a sealing sheet, such as a laminate sheet, is adheredto the upper part of the neck 11 to seal the opening until the bottle isused.

FIGS. 11-13 show a synthetic resin bottle in the 6th embodiment of thisinvention. The bottle 1 of this embodiment is formed by blow molding asynthetic resin material, and comprises a pair of flat central walls 15facing each other, a pair of hog-backed walls 16 having a nearly arcshape in the plan view and protruding right- and leftward from thecentral walls 15, and tapered walls 17 and 18 disposed at the upper andlower ends of each hog-backed wall 16.

The shoulder 2 allows the neck 11 to stand thereon, has a roughlyrectangular shape on the plan view, and is disposed on the upper part ofthe body 3. The bottom 4 has also a roughly rectangular shape, and isdisposed on the lower part of the body 3, as if the bottom 4 is anextension of the flat central wall 15 of the body 3. In the centralframe, the bottle 1 has a configuration that, except for the neck 11,flat walls surround the central portion along the nearly entire verticalcircumference.

The shoulder 2, the bottom 4, and the central walls 15 of the body 3 aremolded to have an ordinary thick wall so that the shell section 8 withhigh rigidity is formed. A pair of right and left hog-backed walls isconnected to the shoulder 2 and the bottom 4 through the tapered walls17 and 18, respectively. Each hog-backed wall 16 protrudes outward for amaximum length corresponding to about a half of the central wall width,and has a relatively thin wall thickness. The tapered walls 17, 18 alsohave a thin wall thickness, and together with the hog-backed walls 16,constitute the reversible sections 10.

The lines of turn 5 in the shape of a shallow V groove for wall bendingare formed on the surface along the border between the shell section 8and both reversible sections 10.

When both reversible sections 10 are pressed inward, they areresiliently reversed from the respective lines of turn 5 and areconcaved into the inside of the shell section 8 for volume reduction(See the chain two-dash line in FIGS. 11 and 12). The reversiblesections 10 are easily restored to the original shape by applying anoutward force in the opposite direction to reverse again these sections10.

The reversible sections 10 of the bottle in this embodiment are concavedand stored inside of the central shell section 8 of a rectangular shapein its plan view, which includes the body 3 and the bottom 4. Therefore,it becomes possible for the bottle 1 to be fully concaved for volumereduction. As described above, the central shell section 8 has aconfiguration that flat walls surround the central portion along thenearly entire vertical circumference. Even in the volume-reduced state,the bottle 1 of this embodiment can fully stand on its own and has goodhandling ability.

In the 5th and 6th embodiments, the portion used as the shell section 8and the portion or portions used as the reversible section or sections10 are formed so as to have different wall thicknesses at the time ofmolding. However, even with these bottles, the entire bottle 1 can bemolded to have a thin wall thickness. Then, a label is attached, or anouter or inner layer is laminated, to form the shell section 8, asdistinguished from the reversible section or sections 10, as shown inthe 2nd, 3rd, and 4th embodiments.

EFFECTS OF THE INVENTION

This invention having the foregoing configurations has the followingeffects.

In the invention of claim 1, about a half each of the shoulder, thebody, and the bottom on one side of the bottle molded by the containermanufacturer can be concaved into the inside of the shell section, andthe entire bottle can be fully flattened for volume reduction, byreversing the reversible section inward.

When bottles are handled in the fully flattened, volume-reduced state,the space of occupancy can be greatly decreased. This lowers the costsof storage and transportation, and makes bottle handling easy andefficient, during the processes followed until bottles are filled withliquid content.

After the reversible section has been restored to the original shape andthe bottle has been used as a container, the reversible section is againconcaved into the inside of the shell section, and the bottle is fullyflattened, with volume reduced, and is put to waste disposal. Anyoneshould be able to fully flatten the bottle after use and dispose of thebottle as waste easily and efficiently.

In the invention of claim 2, the reversible section protrudes in asemi-arc shape as seen in the plan view. This reversible section can bedeformed and concaved into the inside of the shell section, which alsoprotrudes in a semi-arc shape, but at a larger diameter than thereversible section. Since the entire bottle can be flattened in acertain shape, and since the flat bottles can be piled up, the storageand transportation of unused bottles and the disposal of used bottlescan be efficiently carried out at a lower cost than usual.

In the invention of claim 3, the neck is disposed on the shell sectionside. This makes it possible for the entire bottle to be flattenedwithout crushing up the neck. Because of this configuration, it hasbecome possible to deform and concave approximately a half of the entirebottle, including the shoulder, the body, and the bottom.

In the invention of claim 4, the neck has also the shell section and thereversible section of its own. In such a configuration, it is possibleto make the entire bottle sufficiently flat over all the height fromneck to bottom.

In the invention of claim 5, two lines of turn are provided, and theright and left reversible sections are concaved into the inside of thecentral shell section. Both reversible sections are concaved and storedin the inside of the central shell section of a rectangular shape in itsplan view, which includes the bottom. Therefore, it becomes possible forthe bottle to be fully concaved for volume reduction. Even in thevolume-reduced state, the bottle can fully stand on its own and has goodhandling ability.

In the invention of claim 6, the laminated bottle wall has higherrigidity than the non-laminated wall, namely, the wall portion of thebottle that has been molded to have usual thin walls. Since there is noneed of changing the wall thickness of the bottle itself for bothsections, bottles can be easily molded by an ordinary blow moldingmethod while maintaining high productivity.

In the invention of claim 7, a label attached to the outer surface ofthe body is used to form the shell section. In this case, the shellsection can be formed easily and at a low cost. Furthermore, since awide area can be secured for the label display, high decorative anddisplay effects can be obtained.

In addition, the rigidity of the shell section is fully enhanced, andthe bottle shows high shape-holding power. Because of these features,the bottle shape becomes stabilized and constant when the bottle isdeformed for volume reduction and also when it is restored to theoriginal shape. The bottle can be allowed to have thin walls with nodifficulty, by making the label serve as a structural material.

In the invention of claim 8, both of the shell section and thereversible section can be formed simultaneously at the time when thebottle is molded. Depending on the portions of the bottle, the ratio ofwall thickness between the shell section and the reversible section canbe changed to make fine adjustments to the rigidity of both sections. Asa result, the reversible section can be concaved into the inside of theshell section and restored to the original shape quite easily.

In the invention of claim 9, the line of turn comprises a sloped step.This line makes it quite easy to reverse and deform the reversiblesection, which can be smoothly concaved and then restored to itsoriginal shape. Since the reversible section is concavely reversed withno permanent deformation, there is no damage to the outer appearancecaused by deformation.

In the invention of claim 10, the line of turn comprises a shallowV-shaped groove. Because of this configuration, reversible sections canbe easily and precisely reversed and deformed into and out of the shellsection.

1. A synthetic resin bottle comprising: at least a line of turn (5)formed on shoulder (2), body (3), and bottom (4) along the entirevertical circumference of a bottle (1); a shell section (8), in which atleast a nearly entire body portion of at least a section has relativelyhigh rigidity, said section being selected from among the sectionsdivided by said line of turn; a reversible section or sections (10)capable of deforming by resilient reversion, which is or are formed inthe other section or sections divided by said line or lines of turn (5),and in which at least a nearly entire body portion in said section orsections have relatively low rigidity; and a neck (11) disposed on theshoulder; wherein the reversible section or sections (10) can bedeformed and easily concaved into the shell section (8) and then can berestored to the original shape.
 2. The synthetic resin bottle accordingto claim 1, wherein a line of turn (5) disposed at the position wherethe plan-view shapes of the shoulder (2), the body (3), and the bottom(4) are divided into two equal, right and left, parts; the shell section(8) comprising a major-diameter portion (6), which is a half portion onone side of said line of turn (5), where the plan view of the body (3)roughly forms an arc-like convex surface having a larger diameter; andthe reversible section (10) comprising a minor-diameter portion (9),which is another half portion on the other side of said line of turn(5), where the plan view of the body (3) roughly forms an arc-likeconvex surface having a smaller diameter.
 3. The synthetic resin bottleaccording to claim 2, wherein neck (11) is disposed so as to stand onthe shoulder at the upper end of the shell section (8).
 4. The syntheticresin bottle according to claim 2, wherein the neck (11) is disposed tostand in the center of the shoulder (2) and wherein a line of turn (5)is formed at the position dividing the plan-view shapes of the shoulder(2), the body (3), and the bottom (4) into two equal, right and left,parts.
 5. The synthetic resin bottle according to claim 1, wherein apair of lines of turn (5) is formed at roughly symmetrical positions inthe plan view of the shoulder (2), the body (3), and the bottom (4),wherein among the sections divided by these two lines of turn (5), theshell section (8) is the central portion where side walls of the body(3) face each other, and wherein the reversible sections (10) are thetwo portions disposed on both sides of the shell section (8), with eachreversible section (10) having an arc-like convex surface in the planview of the body (3).
 6. The synthetic resin bottle according to claim1, wherein the bottle (1) is molded from a relatively soft syntheticresin so as to have a thin wall and wherein on at least either one ofthe inner surface or the outer surface of the shell section (8), themost part of at least the surface of the body (3) is laminated withanother layer.
 7. The synthetic resin bottle according to claim 6wherein a relatively thick, hard label (7a) is laminated over the outersurface of the bottle (1).
 8. The synthetic resin bottle according toclaim 1, wherein the shell section (8) of the bottle (1) is molded so asto have an ordinary thick wall, with the reversible section (10) beingmolded so as to have a thin wall.
 9. The synthetic resin bottleaccording to claim 1, wherein the line of turn (5) comprises a slopedstep.
 10. The synthetic resin bottle according to claim 1, wherein theline of turn (5) comprises a shallow V-shape groove.